(a) Field of the Invention
The present invention relates to a display panel and a manufacturing method thereof.
(b) Description of the Related Art
A liquid crystal display (“LCD”), a plasma display panel (“PDP”) and an organic light emitting device (“OLED”) are among widely used flat panel displays.
These display devices include at least one display panel, and the display panel includes switching elements connected to field generating electrodes and a plurality of signal lines such as gate lines and data lines to apply the voltages to the field generating electrodes by controlling the switching elements. To reduce an afterimage of the display device and to improve the resolution, the resistance of the signal lines may be relatively low.
Particularly, according to an increase of the size of the display devices, a more improved response speed is required to obtain high quality, and research to reduce the resistance of the signal lines has actively progressed.
For a signal line with low resistance, a method in which a low resistance metal such as aluminum (Al), copper (Cu), and silver (Ag) is deposited and patterned by photolithography has been proposed, but the low resistance metal has a poor adhesion characteristic with a glass substrate and may be diffused into a lower layer or an upper layer such that the reliability when the low resistance metal is adapted to the actual process is decreased. Additional processes are required to compensate for this problem.
Also, to reduce the resistance of the signal lines, the metal may be thickly deposited. However, the substrate may be bent during the deposition process and the photolithography process such that it is difficult for the thickening of the signal lines to be reliably executed. Also, in LCDs, the liquid crystal alignment may be influenced by a stepped structure of the metal layers in the liquid crystal display such that light leakage may be generated.